This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. More than half of the proteins in a genome contain metals, which have catalytic and/or structural roles. They therefore play a significant part in a considerable number of physiological functions. This proposal primarily focuses on the visualization of conformations and structural changes of (i) Cu-enzymes and their complexes of the denitrification pathway and (ii) proteins involved in neurodegenerative diseases due to their susceptibility to aggregate, here with a particular emphasis on Cu, Zn superoxide dismutase. In the absence of any structural information SAXS can provide valuable ab initio 3D shapes at low to medium resolution. Yet our complementary crystallographic work will allow us to exploit the scattering data meaningfully in particular in view of conformational changes or associations of molecules whose individual structures are known.